How to LeftClick To Punch?

What Keycode For Left Click here script for punch :

local player = game.Players.LocalPlayer
local db = true
local damage = false

local anim = Instance.new("Animation")
anim.AnimationId = "http://www.roblox.com/asset?id=3582012915"

game.Players.LocalPlayer.Character:WaitForChild("RightHand").Touched:Connect(function(hit)
    if hit.Parent:FindFirstChild("Humanoid") and not db and not damage and hit.Parent.Humanoid ~= game.Players.LocalPlayer.Character.Humanoid then
        if game.Players.LocalPlayer.Character.Humanoid.Health > 0 then
            damage = true
            game.ReplicatedStorage.Punch:FireServer(hit.Parent.Humanoid)
        end
    end
end)

game:GetService("UserInputService").InputBegan:Connect(function(input, event)
    if input.KeyCode == Enum.KeyCode.F and db then
        db = false
        local playAnim = game.Players.LocalPlayer.Character:WaitForChild("Humanoid"):loadAnimation(anim)
        playAnim:Play()
        wait(0.8)
        damage = false
        db = true
    end
end)